Some reproducing apparatus that reproduce music content have a function called a play list with which a user can freely designate a reproduction order of a plurality of music contents. A play list can be freely edited and stored in a file. Thus, the user can store his or her designated reproduction order of his or her favorite music contents and listen to them in the stored reproduction order at any time.
Moreover, in recent years, a technique of categorizing music contents based on their characteristics such as song name, artist name, genre, tempo, released year, number of reproduction times, and so forth and automatically creating a list of contents including common characteristics has been proposed (refer to Japanese Patent Application Laid-Open (translation version of PCT international publication) No. 2005-526340). This list that was created in such a manner is also referred to as a play list. As storage (record) capacities of hard disks, optical discs, and semiconductor memories are increasing, it is becoming difficult for the user to know whole music contents stored (recorded) thereon. In this situation, with a play list, the user can easily listen to his or her desired music contents.
If the user wants to listen to music content A that was released in 1998, it is rare that he or she exactly memorizes its released year. In this situation, if a play list such as “the last half of the 90s” has been created, he or she can listen to music content A by selecting the play list and performing the reproduction process.
Moreover, in recent years, a technique of changing reproduction modes of music contents corresponding to the user's body motions has been proposed. Japanese Patent Application Laid-Open No. 2005-156641 publication describes a reproduction mode controlling apparatus that detects user's walking and running tempos and changes the reproduction speeds of music contents corresponding to the detected tempos.
As the storage capacity of record mediums increases, the number of music contents stored thereon increases. Thus, the quantity (number) of music contents assigned to one play list increases. For example, to allow a play list to deal with human's ambiguous memory like the foregoing released year, the play list has to have a margin of common characteristics of music contents such as “the last half of the 90s” instead of strictly “1998”. Thus, the number of music contents corresponding to one play list becomes large.
Normally, when a plurality of music contents is assigned to one play list, the reproducing apparatus side properly shuffles the music contents and reproduces them at random. Thus, it was likely that music contents to which the user wants to listen is not reproduced, namely music contents corresponding to user's preference are not reproduced. Although the user can manually select his or her favorite music content, if he or she is walking or running, it is difficult for him or her to perform such an operation.